As stated in the QE manual, A is in angstrom whereas alat is in Bohr. Cheers, Vahid
On May 12, 2025, at 7:54 PM, Sri Matta via users <[email protected]> wrote: CAUTION: The Sender of this email is not from within Dalhousie. Hi all Recently started using QE. I have query on ‘alat’ units from input file to output in ‘vc-relax’. Input alat= 8.04590 and the vc-relaxed file the alat is about 15. Both input and out put are copied below. I know the vc-relax will do full relaxation of cell parameters. But changing the value to almost ‘double’? I have a doubt, if it is converting some units in out put? Can anyone help me to understand? ------------------------------------------------ My input parameters (partly: relevant to question) &SYSTEM degauss = 2.0000000000d-02 ecutrho = 3.6000000000d+02 ecutwfc = 4.5000000000d+01 ibrav = 0 A = 8.04590 nat = 10 nosym = .true. ntyp = 4 occupations = 'smearing' smearing = 'cold' input_dft='PBE' / &ELECTRONS conv_thr = 1.0000000000d-08 electron_maxstep = 1080 mixing_beta = 4.0000000000d-01 / &ions ion_dynamics = 'bfgs' / &CELL cell_dynamics = 'bfgs' cell_dofree = 'all' / CELL_PARAMETERS {alat} 1.000000000000000 0.000000000000000 0.000000000000000 0.000000000000000 1.000000000000000 0.000000000000000 0.500000000000000 0.500000000000000 0.622894890565381 ATOMIC_SPECIES OUTPUT (from vc-relaxed) CELL_PARAMETERS (alat= 15.20454743) 0.907043787 -0.000224450 0.000167008 -0.000224449 0.907044034 0.000167012 0.453512311 0.453512433 0.639596537 _______________________________________________________________________________ The Quantum ESPRESSO Foundation stands in solidarity with all civilians worldwide who are victims of terrorism, military aggression, and indiscriminate warfare. -------------------------------------------------------------------------------- Quantum ESPRESSO is supported by MaX (www.max-centre.eu<http://www.max-centre.eu/>) users mailing list [email protected]<mailto:[email protected]> https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________________________________________ The Quantum ESPRESSO Foundation stands in solidarity with all civilians worldwide who are victims of terrorism, military aggression, and indiscriminate warfare. -------------------------------------------------------------------------------- Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
